package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.config.RedissonConfig;
import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonConfig redissonConfig;
    @Autowired
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;

    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init() {
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable {
        String queueName ="stream.orders";
        @Override
        public void run() {
            while (true) {
                try {
                    //获取消息队列订单中队列信息 XREADGROUP GROUP g1CI COUNT1BLOCK 2000 STREAMS streams.order >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    //判断消息获取是否成功
                    if (list==null || list.isEmpty()) {
                        //获取失败说明没有消息，继续下一次循环
                        continue;
                    }
                    //解析消息中订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //获取成功，可以下单
                    handleVorcherOrder(voucherOrder);
                    //ACK确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());

                } catch (Exception e) {
                    log.error("处理订单异常", e);
                    handlePendingList();
                }
            }
        }

        private void handlePendingList() {
            while (true) {
                try {
                    //获取pending-list订单中队列信息 XREADGROUP GROUP g1CI COUNT1BLOCK 2000 STREAMS streams.order >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    //判断消息获取是否成功
                    if (list==null || list.isEmpty()) {
                        //获取失败说明没有pending-list异常消息，结束循环
                        break;
                    }
                    //解析消息中订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //获取成功，可以下单
                    handleVorcherOrder(voucherOrder);
                    //ACK确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());

                } catch (Exception e) {
                    log.error("处理pending-list异常", e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        throw new RuntimeException(ex);
                    }
                }
            }
        }
    }

//    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
//    private class VoucherOrderHandler implements Runnable {
//        @Override
//        public void run() {
//            while (true) {
//                try {
//                    //获取订单中队列信息
//                    VoucherOrder voucherOrder = orderTasks.take();
//                    //创建订单
//                    handleVorcherOrder(voucherOrder);
//                } catch (Exception e) {
//                    log.error("处理订单异常", e);
//                }
//
//            }
//        }
//     }

    private void handleVorcherOrder(VoucherOrder voucherOrder) {
        //获取用户
        Long userId = voucherOrder.getUserId();
        //创建锁对象
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //获取锁
        boolean islock = lock.tryLock();
        //判断是否获取锁成功
        if (!islock) {
            //获取锁失败，根据实际情况，返回错误或者重试
            log.error("一个人只允许下一单！");
            return;
        }
        try {
            proxy.createVoucherOrder(voucherOrder);
        } finally {
            //释放锁
            lock.unlock();

        }
    }


    private IVoucherOrderService proxy;

    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        //获取订单id
        long orderId = redisIdWorker.nextId("order");
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT, Collections.emptyList(),
                voucherId.toString(), userId.toString(), String.valueOf(orderId)
        );
        //判断结果是否为0
        int r = result.intValue();
        if (r != 0) {
            //不为0，代表没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
        //获取代理对象（事务）
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //返回订单id
        return Result.ok(orderId);
    }

//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //获取用户
//        Long userId = UserHolder.getUser().getId();
//        Long result = stringRedisTemplate.execute(
//                SECKILL_SCRIPT, Collections.emptyList(), voucherId.toString(), userId.toString()
//        );
//
//        //判断结果是否为0
//        int r = result.intValue();
//        if (r != 0) {
//            //不为0，代表没有购买资格
//            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
//        }
//        //为0，有购买资格，把下单信息保存到阻塞队列当中
//        //创建订单
//        VoucherOrder voucherOrder = new VoucherOrder();
//        //订单id
//        long orderId = redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        //用户id
//        voucherOrder.setUserId(userId);
//        //代金券id
//        voucherOrder.setVoucherId(voucherId);
//        //放入阻塞队列
//        orderTasks.add(voucherOrder);
//        //获取代理对象（事务）
//        proxy = (IVoucherOrderService) AopContext.currentProxy();
//        //返回订单id
//        return Result.ok(orderId);
//    }

//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //查询优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        //判断秒杀是否开始
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            //尚未开始
//            return Result.fail("秒杀尚未开始！");
//        }
//        //判断秒杀是否结束
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("秒杀已经结束！");
//        }
//        //判断库存是否充足
//        if (voucher.getStock() < 1) {
//            return Result.fail("库存不足！");
//        }
//        Long userId = UserHolder.getUser().getId();
//        //创建锁对象
//        //SimpleRedisLock lock = new SimpleRedisLock(stringRedisTemplate, "order:" + userId);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        //获取锁
//        boolean islock = lock.tryLock();
//        //判断是否获取锁成功
//        if(!islock){
//            //获取锁失败，根据实际情况，返回错误或者重试
//            return Result.fail("一个人只允许下一单！");
//        }try {
//            //获取代理对象（事务）
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        }finally {
//            //释放锁
//            lock.unlock();
//        }
//    }

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //一人一单
        Long userId = voucherOrder.getUserId();

        //查询订单
        int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        //判断是否存在
        if (count > 0) {
            log.error("用户已经购买过一次！");
            //用户已经购买过了
            return;
        }
        //减扣库存
        boolean success = seckillVoucherService.update()
                .setSql("stock=stock-1")
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0)//where id=? and stock>0
                .update();
        if (!success) {
            log.error("库存不足！");
            //扣减失败
            return;
        }
        save(voucherOrder);
    }

//        @Transactional
//        public Result createVoucherOrder(Long voucherId) {
//            //一人一单
//            Long userId = UserHolder.getUser().getId();
//
//            //查询订单
//            int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
//            //判断是否存在
//            if (count > 0) {
//                //用户已经购买过了
//                return Result.fail("用户已经购买过一次！");
//            }
//            //减扣库存
//            boolean success = seckillVoucherService.update()
//                    .setSql("stock=stock-1")
//                    .eq("voucher_id", voucherId).gt("stock", 0)//where id=? and stock>0
//                    .update();
//            if (!success) {
//                //扣减失败
//                return Result.fail("库存不足！");
//            }
//            //创建订单
//            VoucherOrder voucherOrder = new VoucherOrder();
//            //订单id
//            long orderId = redisIdWorker.nextId("order");
//            voucherOrder.setId(orderId);
//            //用户id
//            voucherOrder.setUserId(userId);
//            //代金券id
//            voucherOrder.setVoucherId(voucherId);
//
//            save(voucherOrder);
//            return Result.ok(orderId);
//        }
}

